What happens when a a short pulse is flicked down a long taut spring It keeps its shape but gets smaller the farther it goes It keeps its shape and stays the same size ID: 562899
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Slide1
Transverse waves on an elastic springSlide2
What happens when
a a short pulse is “flicked” down a long, taut spring?
It keeps its shape but gets smaller the farther it goes.It keeps its shape and stays the same size.It changes shape, but stays about the same size.It changes shape, and gets smaller.I have no clue.
NEXUS/Physics Clicker QuestionsSlide3
What happens?
NEXUS/Physics Clicker QuestionsSlide4
If this is the space-graph (photo at an instant
of time) what does the time-graph look like for the bead marked with a red arrow?
Choice OneChoice TwoChoice ThreeChoice Four
y
x
Pulse moving to the right
Choice Five
Choice Six
Choice Seven
Choice Eight
NEXUS/Physics Clicker QuestionsSlide5
Describing the motion
of the beadsSketch vertical arrows showing how each bead is moving as the pulse moves from the first position to the second.
y
x
Pulse moving to the right
v
y
x
NEXUS/Physics Clicker QuestionsSlide6
A
pulse is started on the string moving to the right. At a time t0 a photograph of the string would look like figure 1 below. A point on the string to the right of the pulse is marked by a spot of paint. (x is horizontal and right, y is vertical and up)
Which graph would look most like a graph of the y displacement of the spot as a function of time?7 None of theseNEXUS/Physics Clicker QuestionsSlide7
A
pulse is started on the string moving to the right. At a time t0 a photograph of the string would look like figure 1 below. A point on the string to the right of the pulse is marked by a spot of paint. (x is horizontal and right, y is vertical and up)
Which graph would look most like a graph of the x velocity of the spot as a function of time?7 None of theseNEXUS/Physics Clicker QuestionsSlide8
A
pulse is started on the string moving to the right. At a time t0 a photograph of the string would look like figure 1 below. A point on the string to the right of the pulse is marked by a spot of paint. (x is horizontal and right, y is vertical and up)
Which graph would look most like a graph of the y velocity of the spot as a function of time?7 None of theseNEXUS/Physics Clicker QuestionsSlide9
A
pulse is started on the string moving to the right. At a time t0 a photograph of the string would look like figure 1 below. A point on the string to the right of the pulse is marked by a spot of paint. (x is horizontal and right, y is vertical and up)
Which graph would look most like a graph of the y force on the spot as a function of time?7 None of theseNEXUS/Physics Clicker QuestionsSlide10
What Controls the Speed of the Pulse
on a Spring?To make the pulse go to the wall faster
Move your hand up and down more quickly (but by the same amount).Move your hand up and down more slowly (but by the same amount).Move your hand up and down a larger distance in the same time.Move your hand up and down a smaller distance in the same time.Use a heavier string of the same length under the same tension.
Use a string of the same density but decrease the tension.Use a string of the same density but increase the tension.Put more force into the wave,
Put less force into the wave.
NEXUS/Physics Clicker QuestionsSlide11
B
elow is a snapshot of a piece of an elastic spring on which a pulse is traveling. Each square of the grid represents 1 cm. In a video of the motion of the pulse, the pulse is observed to move a distance of 2 cm in 0.04 seconds. Three pieces of tape are attached to the spring. They are marked by small circles in the figure and are labeled A , B , and C . Graph the velocity of each of the 3 pieces
of tape as the pulse moves past them.(Take this instant as t = 0)NEXUS/Physics Clicker QuestionsSlide12
Graph I
Graph II
Graph III
Which goes
with which?
NEXUS/Physics Clicker QuestionsSlide13
How do waves combine?
We know how one pulse moves. What happens when we get two pulses on top of each other?
?
NEXUS/Physics Clicker QuestionsSlide14
What happens
if they overlap perfectly?
?
NEXUS/Physics Clicker QuestionsSlide15
What happens when they would have passed each other if the other hadn’t been
there?
?
1.
2
.
3
.
4
.
Other
(Bounce off)
(Pass through)
(Cancel)
NEXUS/Physics Clicker QuestionsSlide16
?
1.
2
.
3
.
Other
NEXUS/Physics Clicker QuestionsSlide17
How about on the same side?
?
NEXUS/Physics Clicker QuestionsSlide18
NEXUS/Physics Clicker QuestionsSlide19
A
n elastic string (modeled as a series of beads) driven by a wheel driving one of the beads up and down sinusoidally. . The driving wheel has generated a traveling wave of amplitude 10 cm moving to the right. (The string continues on for a long way to the right as indicated by its going “out the window.”) The figure shows t = 0, when the green bead marked “II” is passing through its equilibrium point.Which of the graphs could serve as the graph of
the vertical displacement of bead II as a function of time?
NEXUS/Physics Clicker QuestionsSlide20
A
n elastic string (modeled as a series of beads) driven by a wheel driving one of the beads up and down sinusoidally. . The driving wheel has generated a traveling wave of amplitude 10 cm moving to the right. (The string continues on for a long way to the right as indicated by its going “out the window.”) The figure shows t = 0, when the green bead marked “II” is passing through its equilibrium point.Which of the graphs could serve as
a graph of the vertical displacement of bead III as a function of time?
NEXUS/Physics Clicker QuestionsSlide21
A
n elastic string (modeled as a series of beads) driven by a wheel driving one of the beads up and down sinusoidally. . The driving wheel has generated a traveling wave of amplitude 10 cm moving to the right. (The string continues on for a long way to the right as indicated by its going “out the window.”) The figure shows t = 0, when the green bead marked “II” is passing through its equilibrium point.Which of the graphs could serve as
a graph of the vertical displacement of the elastic string at the time t = 0 as a function of position?
NEXUS/Physics Clicker QuestionsSlide22
Graph A is a graph of the string's shape and graph B is a graph of the string's
velocity. Is the wave on the string: a right going traveling wave a left going traveling wave a part of a standing wave growing in amplitude at time t1
a part of a standing wave shrinking in amplitude at time t1none of the above you can’t tell from the info given. NEXUS/Physics Clicker QuestionsSlide23
Graph A is a graph of both the string's shape and the string's velocity
. Is the wave on the string: a right going traveling wave a left going traveling wave a part of a standing wave growing in amplitude at time t1 a part of a standing wave shrinking in amplitude at time
t1none of the above you can’t tell from the info given. NEXUS/Physics Clicker QuestionsSlide24
Graph B is a graph of the string's shape and graph A is a graph of the string's velocity
. Is the wave on the string: a right going traveling wave a left going traveling wave a part of a standing wave growing in amplitude at time t1
a part of a standing wave shrinking in amplitude at time t1none of the above you can’t tell from the info given. NEXUS/Physics Clicker QuestionsSlide25
This is the state of the PhET wave-on-a-string simulation when the string is very long so reflection can be ignored.
What is the speed of the wave (assuming that the frequency is given in cycles/min?NEXUS/Physics Clicker QuestionsSlide26
For what frequencies will
we generate a large (resonant) standing wave if we drive it with a small amplitude?NEXUS/Physics Clicker QuestionsSlide27
If we start our beaded string off
in a sinusoidal shape y(x) = A sin(πx/L) it will oscillate with a frequency f0.If we start it out with a shape y(x) = A sin(2πx/L)with what frequency will it oscillate?
f02f0f0/2Something elseNEXUS/Physics Clicker QuestionsSlide28
If we start our beaded string off
in a sinusoidal shape y(x) = A sin(πx/L) it will oscillate with a frequency f0.If we start it out with a complex shape (shown) will it ever repeat itself? If yes, with what frequency? Nof
02f0f0/2Something elseNEXUS/Physics Clicker QuestionsSlide29
In the figure below is shown a picture of a string at a
time t1. The pieces of the string are each moving with velocities indicated by arrows. (Vertical displacements are small and don't show up in the picture.) if the shape of the string at time t1 is that shown below (displacement magnified by X100) then the motion of the string isLeft traveling wave
Right traveling waveA standing wave increasing in amplitudeA standing wave decreasing in amplitudeNone of these.NEXUS/Physics Clicker QuestionsSlide30
In the figure below is shown a picture of a string at a time
t1. The pieces of the string are each moving with velocities indicated by arrows. (Vertical displacements are small and don't show up in the picture.) if the shape of the string at time t1 is that shown below (displacement magnified by X100) then the motion of the string is
Left traveling waveRight traveling waveA standing wave increasing in amplitudeA standing wave decreasing in amplitudeNone of these.NEXUS/Physics Clicker QuestionsSlide31
In the figure below is shown a picture of a string at a time
t1. The pieces of the string are each moving with velocities indicated by arrows. (Vertical displacements are small and don't show up in the picture.) if the shape of the string at time t1 is that shown below (displacement magnified by X100) then the motion of the string is
Left traveling wave
Right traveling wave
A standing wave increasing in amplitude
A standing wave decreasing in amplitude
None of these.
NEXUS/Physics Clicker Questions